On Nov. 9, after three years of development, months of frenzied fan speculation and $75 million in pre-orders, Microsoft launched Halo 2, the sequel to the top-selling title for the Xbox video game console. And from the moment Halo 2 finally went on sale, gamers have burned countless hours mastering Halo 2's fancy new weapons and exploring its expanded humans-repel-alien-invaders narrative. But for filmmakers like Burnie Burns, who work in the emerging medium of machinima, these features are a mere starting point. Instead of playing Halo as intended, Mr. Burns and a crew of machinima peers exploit the game's software quirks to create their online comedy series, Red vs. Blue, within Halo's virtual world. Since its debut in the spring of 2003, Red vs. Blue has rivaled Halo itself in popularity; fans download new episodes (www.redvsblue.com) at a rate of over 900,000 a week.

GREG ALLEN How did you start making short films inside a video game?

BURNIE BURNS I made a 16-millimeter, then the guys I made it with left for L.A. I stayed [in Austin, Tex.] working for a technology company, and basically, I needed a way to write and produce stuff myself. That's when I had the idea.

Q How do you pronounce machinima? It's one of those words that nobody ever says out loud.

A I've heard it pronounced both mah-SHIH-ni-ma and mah-SHEE-ni-ma.

Q What's the basic machinima process?

A One player in a game is literally a cameraman; you're recording through that character's eyes. It looks like animation, but it's really a lot like live action. You block out a scene and do takes. Then you edit it and dub your own dialogue. Machinima kind of starts when you stop playing. Halo is a virtual world; a character's programmed to talk or shoot when a player enters the room, but what happens right after the player leaves? He's still in there.

Q So you're exploring the inner lives of these faceless, armor-clad warriors?

A Exactly. We imagined our own characters and storyline. Sometimes it intersects with the Halo story, like the episode when Sarge calls [their vehicle] the Warthog, and the others think it looks like a puma. But mostly we just tell our own stories.

Q One of the trademarks of Red vs. Blue is Halo's spare, almost Beckettian landscape. How does Halo 2, which is more elaborate, change things for you? Is it like when they try to revitalize a sitcom by redecorating?

A Yeah, or relocating, like when Laverne & Shirley moved to California. [The Halo 2 developers at Bungie] have their own storyline, but we'll still do the absurdist existential comedy. They've upgraded the world; the lighting's different, the rocks are different. They've rendered the characters in much higher detail. But the main thing for us is the new models; now you can control the aliens like you control the marines. So we can do real-world parallels of wars or cultural differences.

A [Laughs] They still could. But the guys from Bungie contacted us right away - they saw it starting at Episode 1 or 2 - and said they liked it a lot and wanted to make sure we were protected. Everyone's got this need to tell a story, and I think more of these big companies recognize that.